反应详情

温度

130 °C

4-Hydroxy-3-isobutyryl-6-isopropyl-pyran-2-one (11.7 g, 52 mmol) was taken up in conc. Sulfuric acid (40 mL) and stirred at 130° C. for 15 mins. The dark oil obtained was left to cool to room temperature and was then cooled further to 0° C. in an ice bath before the addition of 200 mL crushed ice with stirring. The resulting solution was extracted with ethyl acetate (3×200 mL) and the combined organics were dried over sodium sulfate, filtered and evaporated in vacuo to a light brown oil that was purified by column chromatography using a gradient of pentane in ethyl acetate 3:1→30:70 as eluant to provide the title compound as a light brown oil which solidified on standing (6.1 g, 77%).

1. customThe dark oil obtained
2. waitwas left
3. temperatureto cool to room temperature
4. temperaturewas then cooled further to 0° C. in an ice bath before the addition of 200 mL
5. customcrushed ice
6. stirringwith stirring
7. extractionThe resulting solution was extracted with ethyl acetate (3×200 mL)
8. dry with materialthe combined organics were dried over sodium sulfate
9. filtrationfiltered
10. customevaporated in vacuo to a light brown oil that
11. customwas purified by column chromatography